James ward packard



(No Model.)

J. W. PACKARD.

' MANUFACTURE OF INOANDESGENT LAMP FILAMENTSQ No. 391,815. Patented001:. 30, 18818.

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I HM I l JAB'IES YARD PACKARD, OF NINV YORK, N. Y.

MANUFACTURE OF lNCANDES'CENT -LAMP FILAMENTS.

E5PECIFICATION forming part of Letters Patent No. 391,815, dated ember30, 1858.

Application filed Apiil 6, 18. 8 Serial No. 269,911. (No specimens.)

To all whom it may concern.-

Be it known that I, J Tiaras WARD PACKARD, a citizen of the UnitedStates, residing at New York, in the county of New York and State of NewYork, have invented certain new and useful improvements in Methods ofIncandescent- Electric-Lamp li'fauufacture; and I do hereby declare thefollowing to be a full, clear, and exact description of theinvenlion,such as will enable others skilled in the art to which it ap' pertainsto make and use the same.-

My invention relates to a certain method employed in the manufacture ofincandescent electric lamps, hereinafter to be described and claimed.

In the drawings, Figure 1 shows a front view and partial section of thepreferred form of apparatus by which my method may be applied. Fig. 2 isa side view of the same, the tank being removed. Fig. 3 illustrates amodification.

In the manufacture of incandescent electric lamps it is customary tofuse or cementthe carbon strip therein used to the platinum electrodesof the lamp by immersing the said carbon strip and electrodes in asuitable solution of carbon-such as hydrocarbon oiland passing theelectric current through the carbon strip and the platinum electrodes, Adep osition of carbon at the joint is thereby produced and theconnection between the electrodes and the ends of the carbon strip madecomplete and permanent. It is evident that for many reasons it is notdesirable to have any considerable portion of the current pass throughthe entire loop formed by the carbon strip. To avoid this it has beencustomary to place a bar of some conductive material of low resistanceacross the loop near where the ends of the carbon strip join theelectrodes. In cases wherea carbon strip of small cross-sec tion-such asthose used in the manufacture of high-resistance lamps-is being operatedupon, it frequently bends and breaks under the weight of the shortcircuiting-bar. To

avoid the above-mentioned dilficulty, the method described in Patent No.353,158, granted to A. L. Iteinmann, November 23, 1886, was devised.While this avoids the difficulty, it is less effective than the originalmethod, because the fusing or cementing current does not pass throughthe ends of the carbon strip which are to be cemented to the electrode.To avoid both the objections to the abovedescribed methods, I havedevised that hereinafter to be described.

In the preferred form of apparatus by which my method may beapplied,(illustrated in the accompanying drawings) T is a tankcontaining hydrocarbon oil, and also a certain quantity of mercury, asclearly shown in Fig. 1.

S is a stand lrd having the bracket 13.

O is abloek of insulating material,to which the clamps, of any suitableconducting material, and the rods 1% It, also of conducting material,are attached. The clamps, as clearly shown in Figs. 1 and 2, consist ofthe parts I) I), attached to the block O and connected, respectively, bysuitable conductingstrips with the rods It It, together with the hingedparts O 0, controlled by the springs s 8'. Within the bracket 13 is thecollar 1, of rubber or other suitable insulating material. The parts Iand l,also of insulating material, completely insulate the sleeve a andthe parts I) b, surrounding the rod R, from the bracket B. The parts a bb are all of conducting material, and being in contact with the bracketH, supporting the binding-post N, they afford electric connection fromthe said binding-post to and through the rod R to the clamp 0. Upon thebracket is supported the bindingpost a and the spring contact-piece lP.\Vhen the metallic collar U, which is adj ustably held upon the rod R bythe set-screw S, comes in contact with the spring-piece P, metallicconnection is complete between the binding-post N and the clamp O. Thecarbon strip formed into a loop, L, has one of its ends held by theclamp O, the other by the clamp G. The platinum electrodes E E areattached mechanically to the ends of the carbon strip, as indicated inFig. 1.

The operation of my method is the following: The carbon strip L is heldby the clamps C O as close as possible to the ends which are to becemented to the electrodes E E. The clampholding frame, consisting ofthe rods R R and the insulating block 0, is then pushed down wardthrough its bearings in the insulatingsta-ndard S until the lowerextremities of the platinum electrodes touch the mercury at the bottomof the tank. The collar U is so ad- ICO justed upon the red R thatsimultaneously with the immersion of the ends of the elec trodes in themercury it touches the springcontact-piece P. Consequently the currentderived from any suitable external source of electricity enters throughthe bindingpost N, passes through the red It, as indicated by the arrow,through the clamp 0, through a small portion of the carbon strip at oneof its extremities, through the platinum electrode E, the mercury, theother electrode, E, and out through a small portion of the carbon stripat its other extremity by way of the clamp O, the rod R, its surroundingsleeve and bracket H, to the binding-post N. By this method of causingthe current to enter the carbon strip near one extremity and pass by wayof the low-resistance circuit, composed of the platinu m electrodes andthe mercury bath, out through the other extremity of the loop, thefusing or cementing current (constituting by far the greater part of theoriginal current) passes directly through the ends of the carbon loopand the ends of the platinum electrodes, which are to be cementedtogether. Thus is produced that intimate contact between the particlescomposing the two surfaces which is necessary to produce the best joint.While thus the advantages inherent in the common method described at theopening of this specification are secured, the carbon loop is free fromany ,weight which might break or bend it, and so the advantages of theReinmann method are also obtained. It is evident that while the greaterpart of the current supplied by the external circuit follows the pathabove traced out, asmall portion of the said current, which I will callthe cleansing current, is forced through the carbon loop and isjustsufficient to heat it to the point of cleansing it from allmoisture, grease, and other impurities without altering its electricalresistance.

If desirable, the mercury shown in Fig. 1 may be dispensed with and theplatinum electrodes E E short-circuited by twisting them together, asshown in Fig. 8, or by any other method desired. This, or someequivalent method of short-cireuiting by a rigid metallic contact, ispreferable on the score of safety, since there is then no possibility offailure, such as would occur if the mercury should escape from theapparatus shown in Fig. 1.

Another advantage of my method is that the circuit is not completed forthe passage of the electric current until the electrodes areshortcircuited by their immersion in the mercury, and consequently alldanger of igniting the hydrocarbon vapor by theincandescence of thestrip of carbon, which might occur should the entire current be forcedthrough it beforeim mersion in the oil, is avoided.

No claim is here made to the apparatus herein described. Such apparatuswill be claimed in a separate application filed by me of even dateherewith.

Having therefore described my invention, both in essence and detail,what I claim as new, and desire to protect by Letters Patent, 1s

The method of cementing suitable electrodes to the carbon strips used inthe manufacture of incandescent electric lam ps,and at the same time ofcleansing the carbon strips,which consists, first, in immersing thecarbon strip, the ends of which are held in contact with the ends of theshort-circuit electrodes, in a hydrocarbon oil; second, in connectingone Wire of an electric circuit with the carbon strip at a point nearone of its extremities, while the other wire is connected to the carbonstrip at a point near its other extremity,and then passing a currentthrough the circuit,whereby the greater portion of the currentsoconducted by the said circuit is passed through the extremities of thecarbon strip and the short-circuited electrodes, while a less portion isshunted through thehigh resistance offered by the loop of the carbonstrip, substantially as described. In testimony whereof I affix mysignature in presence of two witnesses.

JAMES WARD PACKARD. \Vitnesses:

A. 1. SMITH, JOHN J. ENNIS.

